Synthesis of diamond-like-carbon coatings by pulsed laser deposition: optimization of process parameters

• Published in: Surface & coatings technology 1999-09, Vol.116-119, p.452-455
• Main Authors: Tabbal, M., Mérel, P., Chaker, M., El Khakani, M.A., Herbert, E.G., Lucas, B.N., O'Hern, M.E.
• Format: Article
• Language: English
• Subjects: Diamond-like-carbon; Elastic modulus; Hardness; Pulsed laser deposition; sp3 content
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/S0257-8972(99)00183-8

In this work, we report on both the microstructural (sp3 carbon atoms content) and the mechanical properties (hardness and elastic modulus) of pulsed laser deposited diamond-like-carbon (DLC) thin films. The sp3 content of the films was determined by analysis of the XPS C 1s core-level signal, and the hardness and elastic modulus were measured by nanoindentation using the continuous stiffness measurement (CSM) technique. By investigating the effect of process parameters, such as deposition temperature and KrF excimer laser intensity on the diamond-like characteristics of the films, we were able to point out that: (1) deposition at 25°C, as opposed to deposition at 300°C, enhances the diamond-like properties of the coatings, (2) the sp3 content increases with laser intensity up to a maximum value of about 60% obtained at 7.0×108 W/cm2 and (3) the hardness and elastic modulus of the coatings both increase with laser intensity as they respectively reach 44 and 375 GPa at 7.0×108 W/cm2. It is finally shown that the observed variations in the hardness value and elastic modulus correlate well with the variations of the sp3 content of the DLC coatings.